Randall Stephens of The Historical Society writes 

"As the semester revs up, quite a few history profs are looking on-line for primary source docs, web-based activities, digital images, and on-line map collections. I use a healthy does of maps and map progressions in the various courses I teach. "

"Yet, quite a few seem to appreciate the historic context of changing boundaries, the view of how landscape shapes culture, the movement of peoples, demographics, and the like. Here are some of the sources I turn to"